For this reason, Allah Most High says:
“If an evildoer brings you news, verify it.”
[Surah al-Hujurāt: 6]
Thus, He commanded verification (1) when an evildoer brings news. It is well known that wrongdoing does not preclude a person from performing an act of obedience or commanding it.
This is also something with which the Imāmis agree, for they do not maintain that those who commit major sins will abide eternally in the Fire (2). Thus, in their view, wickedness does not nullify [all] (3) good deeds (* unlike the Zaydis, the Mu‘tazilites, and the Kharijites, who disagree on this matter and maintain that wickedness nullifies all good deeds *) (4). If all his good deeds were nullified (5), his faith would be nullified; and if his faith were nullified, he would be (6) an unbelieving apostate and would therefore have to (7) be killed.
The texts of the Book and the Sunnah, as well as the consensus (8), establish that the adulterer, the thief, and one who falsely accuses another of illicit sex are not to be killed; rather, the prescribed punishment is carried out upon them. This proves that such a person is not an apostate.
Likewise, the words of Allah Most High:
“If two groups of believers fight, make peace between them”—to the end of the verse—
[Surah al-Hujurāt: 9]
indicate (9) that faith and brotherhood remain despite fighting and aggression.